Stop mechanism.



J. KIEWICZ; s10? MECHANISM.

APPLICATION FILED SEPT- 29, 1914.

1,223,397; Patented 'Apr. 24, 1917.

TED sTAT sPATEN OFFICE.

JOHN KIEWICZQOFHYDE- PARK, MAssAonusn s, ASSIGNOR To THE nnncn BUTTON HOLE Macnnvn COMPANY, or BosToN; MASSACHUSETTS, n CORPORATION or MAI E.

To all whom it may 0011062161 Be it known that Lilo- RN KInWIcz, a citizen of the United States, residing at Hyde Park, in the county of Suffolk and State of Massachusetts, have invented certain new and usefulImprovements in Stop Mecha-' nisms, of which the following is aspecifica. tion, reference being had therein to the accompanying drawing. a

This invention relates to stop mechanisms and more particularly to a mechanical contrivance associated with the driving mechanisms of machines of various sorts for effecting the stoppage thereof in a desirable manner.

An object anddurable stop :mechanism adapted to employmentwith light, fast rotating machines such as sewing machines, power driven from a continuously rotating shaft.

Another obj ectis to providea stop mechanism which isveasily controlled and'operated and serves to promptly,'yet without shock, bring the main shaft of the machine to rest preferably with the nedlesor other operating parts of the machine at apredetermined point in the cycle of their operations.

Qther objects hereof will be perceived from the hereinafter following description of an illustrative mechanism embodying the principles of this invention. i

To the attainment of the objects referred to the present invention consists in the novel combinations, arrangements, mechanisms, devices, details and other features illustratedor described herein. 3 Figure 1 is a front elevation of of a sewing machine embodying a stop mechanism constructed on the principles of this -invention,, the front side being broken away to disclose the interior. 1

Fig. 2 isa bottom' plan view of the mecha nism shownin Fig. 1 partly in section taken on the plane 2-2 of Fig. 1.-

Fig.3 is'a rightelevation thereof.

Fig. 4 is a perspective view showing the combined fast pulley and braking and stoppine member or camin its-position when the madhine is stoppe 4 The same,;reference numerals designate correSpOnding parts in the several views of the drawings.

For convenience of illustration, the general type of sewing machine illustrated in prior Patent No. 1,047 ,537 .of-December 17th,

Specification of Letters Patent.

hereof is to afford an eflicient a portion sTor MECHANISM.

Patented Apr. 24., 1917.

' Application filed September 29,1914. Serial No. 864,010.

1912, hasbeen selected and such prior patent may be referred to forthe general operation of such a machine and for various details not constituting per 86 the present invention.

The main shaft 10 extends from the driving mechanism to the stitching mechanism and operates the needles and cooperating parts.

A resser-foot 11 is shown carried at the forward end of the arm 12 of a swinging lever'the. shaft 13 of which affords a pivotal bearing and also carries a second or actuating arm 14 extending within the frame 9. The arm 14 has at its extremity an extension 15 to permit the lifting of the presser-fo'ot against spring 16. The part which depresses the extension 15 for lifting the resser-foot is shown as one arm 17 of a bell crank lever, whose other arm 18 extends downwardly for the .purpose of the-actuation of the bell crank and for certain other purposes as are below described. I

The lower end of the arm 18 of the bell crank lever 17, 18 is shown constructed as follows. It has a laterally or forwardly extending portion 19 by which it is actuated, and the extremity "of the extension 19 has an offset portion 20 forming a stop which con tacts the interior of the right hand wall of the machine frame'or casing 9, when the parts arefin stopped position, as they are shown in all the figures. The lower part of the'arm 18 is also provided with a contact portion orsur-face 21 which cooperates with a certainpart 30for actuating the latter, as will be laterv described.

The bell crank lever 17 18 controls the adjustment of. the driving mechanism between runningv and stop position and the actuation of the bell crank, for the purpose of control, may be regulated as follows.

Beneath the hollowframej9 of the machine is a base or tray 22 and on this is mounted a pivotal support 23* for a bell crank lever 24, the, horizontal arm of which may be pulled downwardly through a rod 25 by means of a foot-treadle or other controller or lever. The base 22 is adapted to be permanently secured to the bench or work table... The frame or case 9 is adapted to be engaged with and disengaged from the base. The bell crank 2a is permanently on the base. hen the frame carrying the working mechanism of the sewing machine is positioned upon the base the upward arm of the bell crank 24 is located to the right of the horizontal extension 19 of the downward arm of the bell crank 17, 18. This arrangement obviates the necessity of coupling and uncoupling the control treadle when detaching the machine frame for adjustment, inspection or repair. It will be observed that the parts are so arranged that the depression of the treadle rod throws the arm 18 to the left thereby lifting the arm 17 and permitting the spring 16 to depress the presser-foot upon the work. When the bell crank 17, 18 resumes stopped position it antomatically effects the lifting of the presserfoot.

Operated by the bell crank 17, 18 is a slide or rod 28 through which the bell crank effects certain adjustments for driving or stopping. The rod serves as a carrier, carrying certain of the parts at its exterior extremity. It is shown sliding in a bearing formed in the machine frame and a special bearing 29 at its left end. Between the bearing 29 and a collar 30 on the rod is a stout spring 31 tending to force the collar and the rod toward the right. As seen in Fig. 1 the contact portion 21 of the arm 18 bears directly against the right face of collar 30 so that when the arm 18 is swung to the left in starting the machine it forces the collar and the rod to the left, while in stopping the machine the spring effects a reverse movement thereof.

All of the mechanisms illustrated within the hollow casing of the machine have now been described. The rod or carrier 28 extends through and beyond the casing to an exterior point adjacent the projecting right hand end of the main shaft 10.

On the main shaft is fixed a fast pulley 32 and adjacent to that the shaft carries a loose pulley 33. A belt 34. is adapted to be shifted from one pulley to the other. A shiftable belt shifter 35 is carried on the rod 28 so as to partake of the longitudinal sliding movementof the latter. The belt shifter constitutes a device for engaging and disengaging the power from the main shaft. The belt shifter is shown as having its'opposed arms formed of a single piece secured by set screw to the slide rod but the two parts of the shifter might be separately constructed and attached so as to permit one of them to be swung, enabling the operator to entirely remove the belt when desired.

Depressing the treadle rod shifts the belt shifter to the left and therefore effects the driving of the machine and on the return of the parts the belt, returning to the loose pulley, ceases to drive the machine.

The parts hereinafter to be described operate in such a way that the carrier or rod 28 may only shift to the right for stopping the machine at a certain definite point in the revolution of the shaft, such shifting being succeeded by nearly one complete revolution of the shaft, during which a brake is first applied to slow down the parts and materially reduce or substantially eliminate the momentum, after which the braking action is discontinued and the shaft is positively stopped by the cushioned impact of two stop members or fingers thus bringing the shaft finally to rest in a predetermined position, and locking it there against rebound. Certain of the parts to be described are mounted at the external end of the carrier rod 28 and may be said to constitute the head of the rod, and others are secured to the main shaft.

A non-rotating stop or finger may be provided in the following manner. Pinned to the external portion of the carrier 28 is a head or barrel 38 within which is a bolt 39, which for the purpose of cushioning the impact, isbacked by a stifi spring 40 at its rear, the spring surrounding an adjusting rod provided with lock nuts 41 for adjusting the normal position of the bolt. At its forward end the bolt carries an upstanding lug or stop finger 12 adapted to cooperate with a rotating stop finger as will be later described. The entire head 38 and the parts carried by it are normally held lifted by spring 43; but the forward end of the head 38 and the nonrotating stop 12 carried thereby are capable of being depressed at certain times in the manner and for the purpose below described.

For braking or slowing down the parts a novel and extremely simple form of brake is herein disclosed. It is shown as consisting merely of a piece of strong spring wire or rod 15 mounted rigidly with relation to the carrier 28 and capable of bearing upon a suitable drum on the shaft, for example. upon the fast pulley 32. The pressure of the spring brake 45 upon the fast pulley not only slows down the shaft but insures the shifting of the belt to the loose pulley at the time of the stoppage of the machine. The brake 45 is shown as of bent form thus giving increased length, simplicity of structure, efficiency, and ease of adjustment. It is shown socketed, for convenience, in the rear extremity of the belt shifter 35 and is held there by a set screw 46. Adjustment of the position of the brake, and therefore its retarding force, may be effected by loosening the set screw 46 and adjusting the brake i5 therein.

For controlling and operating the. described parts the devices, more particularly shown in perspective in Fig. 4, may be employed. These comprise the'rotating stop,

Extended leftward from the fast pulley is a hub 49 and projecting radially therefrom is a rotating stop lug 50 adapted to coiiperate in the stopping of the machine with the non-rotating lug 42. One of the lugs is axially shiftable with respect to the other. As already described the lug 42 shifts axially through the shiftingof the carrier rod 28 so that it can be moved into and out of the path of the rotatinglug. The action might A be reversed and a similar operation attained by a bodily shifting of all of the parts shown in Fig. 4 along or with the shaft carrying them. It will be understood that the impact of lug 50 against lug 42 is cushioned by the bolt and spring 39, 40, previously described. The rear portion of the rotating lug 50 is beveled off giving an inclined surface 51 for a purpose to be described. When the non-rotating lug 42 is in contact with the rotating lug it is adapted to be there locked against rebound by a stop or look 52, see Figs. 3 and 4. Surrounding the hub 49 is shown also a cam or spiral surface 53 which serves for applying the brake 45. The apex of this spiral cam is identical with the rebound stop 52, these two elements being combined thus adding to the simplicity of the structure. Mgreover the left hand surface of the parts 53, 52 forms a guard 54 which prevents the non-rotating stop from shifting axially into operative position until the proper point in the shafts revolution. The guard surface 54 is continued, as plainly seen in Fig. 4, until it passes into the inclined or beveled surface 51. I a

The operation in stopping the machine carrier rod 28 and all the parts carried by it are in theirleftward position. At this time the non-rotating stop lug 42 is held up by the spring 43 in contact with the cylindrical periphery'of the hub 49. The belt is,

of course, held on the fast pulley 32. The

brake 45 is to the left of the fast pulley out of the way of thetbelt. When the treadle rod 25 is released for stopping the machine the spring 31 seeks to force the carrier rod 28 to the right thus tending to shift all the parts to stopped position, but the non-rotating lug 42 is to the left of the guard surface 54 and the parts are thus prevented from shifting to the right. The guard surface terminates at the incline 51 and at this point the lug-42 is permitted to shift to the right so that the carrier rod 28 and all the parts carried by it shift. By this arrangement the shifting always takes place at a given point in the shafts rotation and, therefore, the breaking and stopping actions always occur in a predetermined manner.- The shifting is accompanied by the shifting of the belt to the loose. pulley. Immediately. the non-rotating lug 42 is dropped into operative position the cam or spiral surface 53 comes into play to press downwardly on the lug 42, gradually lowering it. This lowering of the lug and the swinging of the head 38 continue for the greater part of a revolution. The effect of this action of the cam 53 is to swing the brake spring or rod 45 downwardly upon the periphery of the fast pulley 32. Thus the parts are braked and slow down considerably, but the adjust ment of the brake is such that the parts will not be prematurely brought to rest. The braking action terminates by the terminus of thecam 53 (or the rebound lug 52, which is identical therewith) passing the lug 42 and permitting the latter to rise to the position shown in Fig. 3. The rotating lug 50 strikes the lug 42 which brings the machine to a stop. The rebound stop 52 prevents rebound. The slight lifting of the lug 42 serves to elevate the brake 45 and discontinue its braking action.

For restarting itis only necessary to depress the treadle rod, shifting the sliding carrier rod 28 to the left, thus removing the lug 42 from the path of the lug 50, and at the same time shifting the belt to the fast pulley.- I

For convenience the rotating member 50 may be termed simply a lug or stop lug. The non-rotating stop 42 may be termed a finger; it serves the triple function of first 'cotiperating with the cam to apply the retarder or friction brake 45, to coiiperate iwith the rotating lug 50 to stop the shaft and to cotiperate with the lock 52 to prevent rebound, it being, moreover, shiftable with the carrier 28 into and out of operative adjustment. The belt shifter 35, also shifted by the carrier, may be termed, during the stopping of the machine, a power uncoupling device. The cam 53, while shown spiral, might obviously be helical if having proper connections for throwing the retarder into operation.

The stop lug 50 is adjacent to the terminusof the cam 53 and is adapted to impact the finger for effecting a definite final stoppage of the shaft at the end of the retard- .ing operation caused by the cam. The

structure of the cam and lug is such as to provide a recess between them adapted to be occupied by the finger when the machine is stopped. This not only locks the shaft against rebound but releases the retarder.

It will thus be seen that there has been described a stop mechanism embodying the features and attaining the objects and advantages referred to and further advantages will be apparent to those skilled in the art. Since many matters of arrangement, design, detail and other features may be varied without departing from the principles hereof, no limitation to such features is intended excepting so far as specified in the appended claims.

What is claimed is:

1. In a stop mechanism the combination with a shaft, a shaft retarder, and a positive stopping means for the shaft, a drum on said shaft with which the retarder contacts, said retarder consisting of an elongated metallic rod having its free end adjacent the drum and its other end supported for swinging movement; the supported end of the rod standing at an angle to its free end and adjustably engaged in a socket whereby the retarding force of the rod may be regulated.

2. In a stop mechanism the combination with a shaft, a retarder, a drum on said shaft with which the retarder contacts, said retarder consisting of an elongated stiff metallic rod having its free end bent sub stantially at right angles to its held end, the free end located to contact upon the drum, and its other end held by a movable holder, and means for moving said holder to cause the rod to bear forcibly against the drum for retarding the shaft.

In testimony whereof, I have affixed my signature in presence of two witnesses.

JOHN KIEWICZ.

Witnesses:

F. A. SHEA, G. C. HILL.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

